There are various automatic tracking control systems, which detect the speed of a preceding vehicle and determine the distance between the subject and the preceding vehicle, that is the inter-vehicle distance, based on the detected speed, and which maintain the distance between the two vehicles in order to support long-distance driving with safety.
An apparatus for indicating a condition of a surrounding area of a vehicle has been known which photographs the surrounding area using a vehicle-mounted camera, and displays an image photographed on a display device. FIG. 1 is a flowchart for showing the specific operation of the moving body/approaching object detecting means according to the prior art. First, in the same manner as in the vibration component extraction, a motion vector (Vx, Vy) with respect to each point (x, y) on the screen and the virtual vanishing point (x0, y0) are input (S21 and S22).
It is determined whether or not the point is a moving body depending upon whether or not the input vector represents movement toward the vanishing point after canceling the offset (S23). Meanwhile, motion vectors each determined as a moving body are detected in respective portions of the moving body on the screen. Therefore, an area including these motion vectors is grouped, so as to generate a rectangular moving body area (S24). A distance from the vehicle to this moving body is then estimated on the position of the lower end of the moving body area (S25).
The distance to the moving body area estimated at this point is stored in a memory. When a moving body area is detected in the same position through processing of a subsequent frame image and the estimated distance to the moving body area is shorter than the estimated distance obtained in the previous frame and stored in the memory, the object included in the moving body area is determined as an approaching object (S26). On the other hand, a distance Z is calculated on the basis of the size of the vector (with the offset canceled) by the following formula (S27): Z=dZ*r/dr wherein dZ is a travel length of the vehicle between the frames, r is a distance from the vanishing point on the screen and dr is the size of the motion vector, which are represented as follows: r=sqrt((x−x0)2+(y−y0)2)) dr=sqrt(Vx2+(Vy−Vdy)2), wherein the distance Z obtained at this point is compared with the distance to the road surface stored as the default distance value (S28). Thus, an object positioned higher than the road surface is determined as an obstacle. Also, when an object is approaching from substantially right behind like a vehicle, a motion vector is obtained in the vicinity of the vanishing point, but its size is very small. Therefore, when the distance Z is obtained in the aforementioned manner, a value representing that the object is positioned below the road surface may be obtained. Since no object is generally present below the road surface, such a motion vector is determined as a moving body, so as to be processed through the moving body area extracting processing S24.
Through the aforementioned processing, an obstacle, a moving body, an approaching object and their distances in the image are obtained on the basis of the respective motion vectors of the points on the screen (S29), and the resultant information is output to the image synthesizing means. The image synthesizing means synthesizes a frame of the rectangular area to be lighted in red on the camera image input from the imaging means and outputs the synthesized image to the display device. The display device displays an image obtained by laterally inverting the synthesized image so as to be in the same phase as an image on a rearview mirror.
However, the prior art provides a driving support system, which includes an apparatus for indicating a condition of a surrounding area of a vehicle from a vehicle-mounted camera merely. As we know, it is impossible to acquire entire information of surrounding via a camera merely. There should be a dead space unable to be informed, if a camera is introduced for capturing image. Furthermore, it is difficult to detect the size of the object near the vehicle according to the prior art. Several points instead of real shape in proportional representation would be introduced to indicate a real-time related map around the vehicle, if the size of the object near the vehicle can't be informed. Obviously, the prior art can't provide integrated and broad functions.
Therefore, it needs to provide an apparatus for providing vehicle integrated and broad alarm information to a vehicle operator by means of introducing plural dimension processing units (DPUs) for rectifying those drawbacks and limitations in operation of the prior art and solving the above problems.